1. Field of the Invention
The present invention relates generally to annular wedging or clamping rings of the type that are extendable about a shaft received within the bearing opening of the hub of a pulley, gear, or the like. The device is intended to engage the hub on the shaft for joint rotation and has complementary wedging surfaces in relative slidable contact with each other, whereby relative axial movement of the wedging or clamping rings causes the inner diameter of the device to be reduced to the shaft diameter, while the outer diameter of the device is increased to the diameter of the bearing opening of the hub.
2. Description of the Prior Art
It is very common to provide devices for locking a hub and a shaft together for joint rotation, with the devices being in the form of cooperating, annular wedges that expand regularly through the application of force tending to increase the outer diameter of the locking device and/or reduce the inner diameter thereof.
Typically, devices of this type include an outer wedging ring, having a constant diameter outside surface adapted to bear against the surface of the bearing opening of a hub, and having a tapered inside surface slidably contacting the complementarily tapered outer surface of an inner wedging ring. The inner wedging ring typically has a constant diameter, cylindrical inner surface adapted to engage the shaft to which the hub is to be coupled so that they may rotate together.
The force for relatively axially shifting the outer and inner wedging rings is often in the form of a circumferential series of screws engageable in threaded openings of one of the wedging rings, although in some cases, they are engageable in threaded openings formed in a third, annular, force-supplying element.
Devices of this type have had the disadvantage that in many instances, the overall length of the device is determined by the length of the force-applying screws or bolts. And, it has been noted that in the prior art devices, the bolts may become "pinched", thus complicating their removal whenever the device is to be disengaged from the hub and shaft.
Still further, in the manufacture of devices of this type it has been difficult, very often, to achieve true concentricity, due to the manner in which they are designed.
Still further, it has also been true that devices of this type have been, in some instances, excessively complicated, require excessive attention to dimensions with precision fits and low tolerancing being required, and with other characteristics that make manufacturing relatively expensive and difficult.